A parking assist device equipped in a vehicle is known (see Japanese Patent Application JP2013-220802A, for example). This device operates to recognize a white line on a road surface as a parking frame using the output of a radar device equipped in the vehicle and set a parking target position in a region partitioned by the recognized white line. The parking assist device described in Japanese Patent Application JP2013-220802A further operates to extract a cloud of reflection points determined as the same object using the output of the radar device. When two clouds of reflection points are extracted and a space having a predetermined width or more exists between the two clouds of reflection points, the parking assist device operates to set the target parking position in the space.
The parking assist device described in Japanese Patent Application JP2013-220802A sets one or more parking frames on the basis of a width of parking frames that is preliminarily set, but the actual parking frames have a variety of widths. Setting of the parking frames may therefore be affected by the errors between the set value of the width of parking frames and the actual widths of the parking frames.